package cn.jll.dev.utils.http;

import javax.servlet.http.HttpServletRequest;


/**
 * @description: 获取IP
 * @author: jinleilei
 * @Version: v1.0
 **/
public class IPUtil {
    private static final String CONST_UNKNOWN = "unknown";
    private static final String CONST_COMMA = ",";

    public static String getRealIP(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if (ip.contains(CONST_COMMA)) {
                ip = ip.split(CONST_COMMA)[0];
            }
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || CONST_UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }
}
